A small mobile/portable oxygen generator, in particular, one that is capable of delivering humidified, pure (greater than 99.9%) oxygen gas at pressures of 5 psi and above, would find many applications in the health services industry, e.g., long-term treatment of patients with respiratory disorders. The majority of patients in the U.S. receive their home oxygen therapy from pressure swing adsorption (PSA) oxygen concentrators, which suffer from numerous technological limitations. In response to the need for a new technology-based oxygen generator that satisfies all the requirements for long-term oxygen therapy in the home, the goal of this proposal is to design, fabricate, and test an electrochemical life support system, capable of providing humidified, but otherwise pure (greater than 99.9%), oxygen gas. The unit will be capable of providing a portable supply of oxygen. It will produce pure oxygen by transferring oxygen diluted in air to a pure oxygen stream, on utilizing a device which resembles both a hydrogen/oxygen fuel cell and a water electrolyzer. The objective is the development of an electrochemical oxygen generator that will offer substantial improvements over alternative technologies in several areas, including: oxygen gas purity (greater than 99.9%), delivered oxygen gas pressure range (5-2,500 psi); system weight (less than 35 lb), system compactness, system power consumption (less than 1 kW), system start-up time, reliability and safety. The system will have the capability for satisfying the real time oxygen needs of a patient in the home, as well as the ability to refill portable high pressure oxygen cylinders. It is estimated that the oxygen generator will cost less than $1,200. The electrochemical oxygen generator technology has both government and other commercial applications. PROPOSED COMMERCIAL APPLICATION: The electrochemical oxygen generator technology will find many applications as a point-of-use oxygen generator, e.g., oxygen generation for patients requiring long-term oxygen therapy in the home. In addition, the electrochemical oxygen generator technology has both government and other commercial applications, e.g., crew life support during military aircraft missions, battlefield life support system that can be used in forward medical treatment areas and in casualty transport vehicles, an "oxygen trickle charger" for commercial aircraft emergency compressed oxygen gas supplies, and hyperbaric oxygen therapy for decompression sickness, air embolism, and carbon monoxide poisoning.